Transfer mechanism for ammunition



May 16, 1967 D. P. TASSIE TRANSFER MECHANISM FOR AMMUNITION 2 Sheets-Sheet 1 Filed NOV. 30, 1965 R m ME 3 M T D.. s A L G U 0 D @SQW H|S ATTORNEY TRANSFER MECHANISM FOR AMMUNITION Filed Nov. 30, 1965 2 Sheets-Sheet 2 INVENTOR DOUGLAS P. TASSI E HIS ATTORNEY United States Patent G f 3,319,524 TRANSFER MECHANISM FOR AMMUNITION Douglas P. Tassie. St. George, Vt, assignor to General Electric Company, a corporation of New York Filed Nov. 30, 1965, Ser. No. 510,526 7 Claims. (Cl. 89-33) This invention relates to weapons having a high cyclic rate of fire, and, more particularly, to a transfer mechanism for moving unlinked ammunition from serial supply means to a Gatling-gun.

The nature of modern warfare is such that weapons capable of extremely high rates of fire are required. Ironically, the necessity for developing high-rate-of-fire weapons has signaled a return to the multiple barrel or Gatlinggun. With the advance of modern metallurgy and other refinements, Gatling-guns per se have been developed to a degree where the speed with which ammunition can be supplied to the revolving barrels has become a highly significant limitation on the rate of fire which can be achieved.

Ammunition for automatic firearms is ordinarily supplied in belts. The belts comprise individual rounds held together by links having two part-circular clips to receive adjacent rounds. By successively adding links and rounds, belts of indeterminate length may be realized. For the Gatling-gun type of weapon, the cartridges must be de-linked before they can be introduced into the bolts. Unfortunately, the delinking mechanism itself has proved to be a limiting factor to the speed with which the rounds may be supplied to the bolts.

For this reason, the use of linkless feed systems otters attractive advantages as a method for delivering ammunition to a Gatling-gun. Such systems are known in the prior art and usually comprise three separate and distinct mechanisms: an exit unit from a linkless feed drum; a conveyor system; and a gun feeder. However, these prior art linkless transfer means have been somewhat complex and do not exhibit the reliability required for a successful modern weapon. Further, they have been relatively bulky and heavy which has limited the practicality of their use in either airborne or ground installations.

It is an object of this invention to provide an improved feed system for linkless ammunition.

It is a further object of this invention to provide a single mechanism which performs the functions of prior art linkless transfer means comprising an exit unit from a linkless feed drum, a conevyor system, and a gun feeder.

It is yet another object of this invention to provide a transfer mechanism for linkless ammunition which is compact and light weight.

It is still another object of this invention to provide a transfer mechanism for linkless ammunition which is relatively simple and highly reliable.

Briefly stated, in accordance with one aspect of the invention, a transfer mechanism is provided which comprises cooperating entrance and exit sprockets having sprocket wheels with round propelling teeth. Unlinked rounds are individually engaged by the teeth on the entrance sprocket and are moved by the entrance sprocket for approximately one-half a revolution to an intermediate position at which they are handed off to the exit sprocket. The exit sprocket, counter-rotating with the entrance sprocket, carries the rounds an additional half revolution to a terminal position where they may be received directly into the bolts of Gatling-gun. In addition to their swinging movement around the entrance and exit sprockets, the rounds are constrained to pivot about points lying on their axes so that they are smoothly shifted to achieve the re-orientation necessary from their attitude within the feed means to the attitude at which they can be acceped into the Gatling-gun bolts.

anger Patented May 16, 11967 Additional objects of this invention, its advantages, scope, and the manner in which it may be practiced will become more readily apparent to persons conversant with the art from the following detailed description of an exemplary embodiment taken in conjunction with the subjoined claims and the drawings of which:

FIGURE 1 is a cutaway view of the transfer mechanism with the upper wall removed to show the internal construction of the mechanism;

FIGURE la is a fragmentary sectonal view of one end of the transfer mechanism entrance sprocket;

FIGURE 2 is a partial cross-sectional view along the lines 2-2 in FIGURE 1;

FIGURE 3 is a partial cross-sectional view along the lines 3-3 in FIGURE 1;

FIGURE 4 is a partial cross-sectional lines 4- 3 in FIGURE 1; and

FIGURE 5 is a partial cross-sectional view along the lines 55 in FIGURE 1.

Referring now to FIGURE 1, there is shown a housing 1 which supports the transfer mechanism' It will be seen that the general progression of rounds through the housing is around and under an entrance sprocket 2, and around and over an exit sprocket 3. The longitudinal axes of the entrance and exit sprockets lie in the same plane and are at an acute angle to one another. The entrance sprocket 2 includes an entrance sprocket wheel 4 having six round-propelling teeth 5 which are shown in FIGURE 2. The exit sprocket 3 has two exit sprocket wheels 6 and 8, each of which also has six round propelling teeth 7 and 9, respectively, as may be seen in FIG- URES 4- and 5. The contour of the teeth vary from wheel to wheel to limit the paths which embraced portions of the rounds may follow as they are propelled by the sprockets.

A shaft 14 having first and second bevel gears 12 and 13 is rotatably supported by a member 11 extending from the housing 1. The first bevel gear 12 engages a third bevel gear 14 fixed to a second shaft 16 to which the entrance sprocket wheel 4 is also fixed. In a like manner, the second bevel gear 13 engages a fourth bevel gear 15 fixed to a third shaft 17 to which the exit sprocket wheels 6 and 8 are also fixed. The third shaft 17 is driven through a fourth shaft 23 by external means which also drives or is synchronized with the barrel-rotating mechanism. The bevel gears 12, 13, 14, and 15 all have the same number of teeth so that the entrance sprocket 2 and exit sprocket 3 rotate in opposite directions and in synchronism. Arrows in FIGURES 25 indicate the direction of rotation for the entrance and exit sprockets.

Unlinked ammunition is taken by the transfer mechanism from a revolving supply of rounds which pass serially into the entrance sprocket 2. Rounds traveling to the transfer mechanism move in a feed channel, not shown in the drawings, disposed circumferentially about the entire gun structure. The nose ends of rounds within the feed channel are separated by roller-spacers 26. The rounds are positively circulated through the feed channel by the action of a second toothed sprocket wheel 27, which is fixed to the entrance sprocket shaft 16, against the roller-spacers 26. Rounds are introduced to the feed channel by scoop sprockets 25. When a given round is first engaged by the entrance sprocket 2., it is traveling at constant velocity because of the disposition of the feed channel with respect to the entrance sprocket. Constant velocity, in this context, means that the nose and base ends of the round are moving at the same velocity as the portions of the entrance sprocket which receive the nose and base.

Although several rounds are shown in transit, these view along the may alternatively be thought of as a single round traveling through the mechanism and caught in stop-action iews in time increments of one-sixth revolution of the .prockets. These rounds are lettered successively, ac- :ording to their positions, a, b, c, d, e, f, g, and It so that he sequence of an example round may be easily folowed. As noted above, the rounds must undergo a subit-antial reorientation of their axes from their attitude lpon entry into the mechanism, the position of round b, 1nd that upon their exit from the mechanism, the posiion of round It. The sequence in which this reorientaion is brought about is vital and may best be understood )y a simultaneous consideration of the several figures.

The path through the mechanism will now be described Jsing the above-noted reference positions occupied by be several rounds as if they were a single round.

Individual rounds engaged by and progressing with the :ntrance sprocket must execute a pivoting motion as well as a lateral translation to provide a portion of the total angular shift of their longitudinal axes which is to be effected. As the entrance sprocket 2 rotates, the nose end 3f the round is guided outwardly away from the longi- :udinal axis of the entrance sprocket along a path defined by guides 13a, 18b, and 180 which project inwardly from the casing walls. The guides 18a and 18b are generally bi-planar; i.e., each has first and second planar portions connected end-to-end by a short jog portion. The inner wall surface 18d functions as a guide for the nose of the round. The base of the round is held in one of six circumferentially spaced recesses 22 near one end of the entrance sprocket so that the pivot point for the radial shift with respect to the entrance sprocket axis is at the base of the round as may best be seen in FIGURE 1a.

The reorientation which the round undergoes as it is propelled by the entrance sprocket 2 may be observed in FIGURES 2 and 3 where its attitude in successive positions b, c, d, and e is illustrated by the representations of the intersections between the round and the cross-sectional planes 2-2 and 3-3, respectively. It may be noted that position a represents a round about to leave the feed channel and enter the transfer mechanism. The overall movement of the round with the entrance sprocket may be called quasi-arcuate since only the center of the base of the round nominally moves in a true are. Preferably, the guides 18a, 18b, 180 are shaped such that points along the longitudinal axis of the round nominally describe a family of toroids during the entrance sprocket phase of the transfer.

The round reaches the point for crossover to the exit sprocket 3, position e, after it has rotated approximately one-half revolution with the entrance sprocket 2. The attitude of the round with respect to both the entrance and exit sprockets is important in the cross-over position. Preferably, projections of the longitudinal axes of the entrance sprocket, exit sprocket, and the round intersect at this instant. This momentary point of intersection 20 is shown in FIGURE 1. With this arrangement, the longitudinal axis of the round is simultaneously a line segment on separate conical paths around the longitudinal axes of the two sprokets. That is, the twoconical paths meet along this single line. Therefore, the transfer of the round from the entrance sprocket to the exit sprocket may be brought about without a violent re-adjustment in its attitude at the crossover point.

The guides 18a, 18b, and 180 which control the movement of the round with the entrance sprocket, terminate adjacent the crossover position, and the round moves smoothly into a slot defined by outer and inner guides 1% and 1% which extend from the housing walls. The base portion of the round is guided into another slot defined by another guide 190 and a stationary cam 19d disposed around the exit sprocket shaft 17. As the round is pulled in a quasi-arcuate path by the exit sprocket, the base of the round follows the cam surface and is forced radially outwardly from the exit sprocket axis thereby. Simultaneously, the head end of the round moves radially inwardly within the slot defined by the guides 19a and 19b,

It can be seen that the pivoting motion of the round during its transit with the exit sprocket is not around the base but, rather is around a point intermediate its ends. Preferably, the pivot point during the exit sprocket phase of the transfer is held at the center of gravity of the round. This is accomplished by coordinating the contour of the cam 19d and that of the guides 19a, 19b, and 190.

The reorientation which the round undergoes as it is propelled by the exit sprocket 3 is shown in FIGURES 4 and 5 where its attitude in successive positions e, f, g, and h is illustrated by the representations of the intersections between the round and the cross-sectional planes 44 and 5-5, respectively.

When the round reaches a terminal position h, it is traveling at constant velocity relative both to the longitudinal axis of the exit sprocket 3 and that of the Gatlinggun. The rotation of the gun is, of course, synchronized with that of the transfer mechanism so that a gun bolt 24 momentarily adjacent the exit sprocket is traveling at the same velocity as a round which it is receiving.

Although the invention has been described in a specific embodiment, it will be appreciated that various modifications and changes may be made by those skilled in the art without departing from the spirit and scope of the invention, and it should not be limited in any sense except as defined by the concluding claims.

What is claimed is:

1. Means for transferring unlinked ammunition from feeder means to a rapid fire gun comprising:

(A) a housing;

(B) rotatable entrance sprocket means having teeth to engage rounds of ammunition available from the feeder means;

(C) first guide means within said housing engaging the rounds so as to move their nose ends radially outwardly from the longitudinal axis of said entrance sprocket means such that the rounds execute a smooth pivoting motion and are propelled through a quasiarcu'ate path as said entrance sprocket rotates;

(D) exit sprocket means having teeth to receive and engage rounds of ammunition available from said entrance sprockets;

(E) second guide means within said housing engaging the rounds so as to move their base ends radial-1y outwardly away from the longitudinal axis of the exit sprocket means such that the rounds execute a smooth pivoting motion and are brought individually and successively into position for hand off to the gun as said exit sprocket rotates; and

(F) torque transmitting means engaging said entrance and exit sprocket means such that said sprockets rotate in synchronism and in opposite directions.

2. The transfer means of claim 1 in which said entrance sprocket means includes notched portions to receive and hold the round bases such that the rounds may pivot about the center of their bases as they are propelled by said entrance sprocket means.

3. The transfer means of claim 2 in which said second guide means cooperate with said exit sprocket means such that rounds propelled by said exit sprocket means pivot about their centers of gravity.

4. The transfer means of claim 2 in which said second guide means cooperate with said exit sprocket means to pull the nose ends of the rounds radially inwardly toward the axis of the exit sprocket means as they are propelled by said exit sprocket means.

5. The transfer means of claim 3 in which said first and second guide means cooperate with said entrance and exit sprockets respectively such that the longitudinal axis of a round momentarily occupying a position between the longitudinal axes of said entrance and exit sprockets and lying in the same plane therewith is oriented such that its projected longitudinal axis intersects at a common point with the projected longitudinal axes of said entrance and exit sprockets.

6. Means for transferring unlinked ammunition from feeder means to a rapid fire gun comprising:

(A) a housing; (B) rotatable entrance sprocket means comprising:

(a) an entrance sprocket shaft having one end extending through a wall of said housing such that said shaft is free to rotate,

(b) an entrance sprocket Wheel fixed to said entrance sprocket shaft,

(0) a base support Wheel fixed to said entrance sprocket shaft and having radially cut, circumferentially disposed equally-spaced notches which extend longitudinally from the portion of the base support wheel nearest said entrance sprocket wheel to termination points short of the portion of the base support wheel furthest from said entrance sprocket wheel, and

(d) an entrance gear fixed to said entrance sprocket shaft outside said housing;

(C) first guide means comprising:

(a) a first guide portion which extends from at least one interior wall of said housing toward, but terminating short of, said entrance sprocket shaft and having portions disposed in a plurality of planes which are parallel to the plane of said entrance sprocket wheel,

(b) a second guide portion extending from an interior wall of said housing towards, but terminating short of, said entrance sprocket shaft and disposed in parallel, spaced apart relationship from said first guide portion along a major portion of the length of said second guide portion, and

(c) a third guide portion extending from at least one interior wall of said housing, the major portion of said third guide portion being disposed Within a plane parallel to the plane of said entrance sprocket wheel, said third guide portion extending beyond said entrance sprocket shaft and having an aperture through which said entrance sprocket shaft passes without constraint against rotation;

(D) rotatable exit sprocket means comprising:

(a) an exit sprocket shaft having a longitudinal axis lying in the same plane as the longitudinal axis of said entrance sprocket shaft and disposed at an acute angle thereto, said exit sprocket shaft also having at least one end extending through a Wall of said housing such that it is free to rotate (b) a first exit sprocket wheel fixed to said exit sprocket shaft,

(c) an exit gear fixed to said exit sprocket shaft,

(d) a second exit sprocket wheel fixed to said exit sprocket shaft, said second exit sprocket wheel being of lesser diameter than said first exit sprocket wheel and being spaced therefrom in a direction away from said exit gear;

(E) second guide means comprising:

(a) a fourth guide portion which extends from at least one interior wall of said housing toward but terminating short of, said exit sprocket shat and having portions disposed in one or mor planes which are parallel to the planes of sail first and second exit sprocket wheels,

(b) a fifth guide portion which extends from a least one interior wall of said housing, said fiftl guide portion having a partition-like portion dis posed in a plane to which the axis of said exi sprocket shaft is normal, said guide portion ex tending beyond said exit sprocket shaft and hav ing an aperture through which said exit sprocke shaft passes without constraint against rotation (c) a sixth guide portion extending from one in terior wall of said housing toward, but terminat ing short of, said exit sprocket shaft, the majo: portion of said sixth guide portion being disposer in a plane parallel to the plane of said exi sprocket wheels,

(d) a cam on the Wall of the housing adjacent saic second exit sprocket wheel away from said exi gear, said cam having a longitudinally borec' aperture disposed such that said exit sprocke' shaft extends therethrough without constraint against rotation, at least a portion of the can having a circumferential cam surface which varies smoothly in distance from the aperture centerline; and

(F) torque transmitting means comprising:

(a) an external shaft rotatably supported along a portion of its length by a sleeve projection from the surface of at least one outer wall of said housing,

(b) first gear engaging means fixed to said external shaft and engaging said entrance drive gear, and

(c) second gear engaging means fixed to said external drive shaft and engaging said exit drive gear.

7. The ammunition transfer means of claim 6 in which:

(A) said entrance gear comprises a bevel gear,

(B) said exit gear comprises a bevel gear,

(C) said first gear engaging means comprises a bevel gear,

(D) said second gear engaging means comprises a bevel gear, and

(E) said external shaft is disposed outside said housing such that its axis falls in the same plane containing the axes of said entrance and exit sprocket shafts.

References Cited by the Examiner UNITED STATES PATENTS 2,815,699 12/1957 Davis 89-33 2,935,914 5/1960 Darsie et a1. 8933 FOREIGN PATENTS 636,252 4/1950 Great Britain.

S. C. BENTLEY, Assistant Examiner. 

1. MEANS FOR TRANSFERRING UNLINKED AMMUNITION FROM FEEDER MEANS TO A RAPID FIRE GUN COMPRISING: (A) A HOUSING; (B) ROTATABLE ENTRANCE SPROCKET MEANS HAVING TEETH TO ENGAGE ROUNDS OF AMMUNITION AVAILABLE FROM THE FEEDER MEANS; (C) FIRST GUIDE MEANS WITHIN SAID HOUSING ENGAGING THE ROUNDS SO AS TO MOVE THEIR NOSE ENGS RADIALLY OUTWARDLY FROM THE LONGITUDINAL AXIS OF SAID ENTRANCE SPROCKET MEANS SUCH THAT THE ROUNDS EXECUTE A SMOOTH PIVOTING MOTION AND ARE PROPELLED THROUGH A QUASIARCUATE PATH AS SAID ENTRANCE SPROCKET ROTATES; (D) EXIT SPROCKET MEANS HAVING TEETH TO RECEIVE AND ENGAGE ROUNDS OF AMMUNITION AVAILABLE FROM SAID ENTRANCE SPROCKETS; (E) SECOND GUIDE MEANS WITHIN SAID HOUSING ENGAGING THE ROUNDS SO AS TO MOVE THEIR BASE ENDS RADIALLY OUTWARDLY AWAY FROM THE LONGITUDINAL AXIS OF THE EXIT SPROCKET MEANS SUCH THAT THE ROUNDS EXECUTE A SMOOTH PIVOTING MOTION AND ARE BROUGHT INDIVIDUALLY AND SUCCESSIVELY INTO POSITION FOR HAND OFF TO THE GUN AS SAID EXIT SPROCKET ROTATES; AND (F) TORQUE TRANSMITTING MEANS ENGAGING SAID ENTRANCE AND EXIT SPROCKET MEANS SUCH THAT SAID SPROCKETS ROTATE IN SYNCHRONISM AND IN OPPOSITE DIRECTIONS. 